Drill bit DeWalt DT8921-QZ for rotary hammer, 7 mm x 210 mm, 1 pc

DeWalt DT8921-QZ 7 mm x 210 mm drill bit is designed for use with rotary hammers and SDS Plus chucks. This single-piece bit features a solid carbide tip with four cutting faces and a four-flute helix to optimise chip evacuation and reduce the chance of jamming when encountering rebar. With a 7 mm diameter and 210 mm overall length, it is sized for creating plug and anchor holes in masonry and concrete during construction, renovation, and installation work.

Advantages

The solid piece carbide tip and body are joined using a robust brazing/welding technique that creates a durable bond for long service life under hammer action. The four cutting faces reduce vibration and improve cutting stability, while the four-flute helix enhances debris removal for faster, cleaner drilling. The SDS Plus shank ensures secure tool engagement and quick bit changes.

Suitable for

• Drilling anchor and plug holes in concrete
• Creating openings in masonry and natural stone
• Renovation and installation work requiring repetitive hammer drilling
• Tasks where rebar may be encountered and jamming must be minimised

Key specifications

• Drill diameter: 7 mm
• Overall length: 210 mm
• Shank type: SDS Plus
• Tip material: solid carbide with four cutting faces
• Flute design: four-flute helix for improved debris removal
• Suitable materials: concrete, masonry, stone
• Package quantity: 1 piece

How to use

Fit the bit into an SDS Plus rotary hammer by inserting and locking the shank according to the tool manufacturer’s instructions. Mark the drilling position and start drilling at low speed to establish the hole, then apply steady hammering force and maintain alignment. Withdraw the bit periodically to clear debris if drilling deep holes. Use appropriate personal protective equipment such as safety goggles, dust mask, and hearing protection when operating the rotary hammer.

Usage recommendations

For best results, use the bit with rotary hammers that support SDS Plus shanks and select a drill mode with hammer action suitable for concrete. Maintain moderate feed pressure to allow the carbide tip to cut effectively and avoid excessive side load. Replace the bit when wear on the cutting faces or significant loss of drilling performance is observed.